feat(coding): add core host api composition

electron/coding-runtime/contracts.ts

@@ -384,6 +384,30 @@ export interface ForkResult {
   snapshot: ConversationSnapshot;
 }
 
+export interface CodingRuntimeCommand {
+  name: string;
+  description?: string;
+}
+
+export type ConversationInteractionResponse =
+  | { interactionId: string; cancelled: true }
+  | { interactionId: string; optionId: string }
+  | { interactionId: string; confirmed: boolean }
+  | { interactionId: string; value: string };
+
+export interface CodingRuntimeDiagnostics {
+  revision: {
+    provider: number;
+    resources: number;
+  };
+  workers: Array<{
+    conversationId: string;
+    generation: number;
+    state: 'spawning' | 'ready' | 'queued' | 'running' | 'idle' | 'crashed';
+    stage: 'starting' | 'idle' | 'queued' | 'running' | 'failed';
+  }>;
+}
+
 export interface CodingConversationRuntime {
   prepare(input: PrepareConversationInput): Promise<ConversationRuntimeState>;
   getSnapshot(conversationId: string): Promise<ConversationSnapshot>;
@@ -397,5 +421,14 @@ export interface CodingConversationRuntime {
   fork(input: ForkConversationInput): Promise<ForkResult>;
   recover(conversationId: string): Promise<ConversationRuntimeState>;
   dispose(conversationId: string): Promise<void>;
+  listCommands(conversationId: string): Promise<CodingRuntimeCommand[]>;
+  listInteractions(conversationId?: string): Promise<ConversationInteraction[]>;
+  respondInteraction(
+    conversationId: string,
+    response: ConversationInteractionResponse,
+  ): Promise<void>;
+  getDiagnostics(): CodingRuntimeDiagnostics;
+  markProviderStale(): void;
+  markResourcesStale(): void;
   subscribe(listener: (patch: ConversationPatchEnvelope) => void): () => void;
 }